AN EMIRATES jet carrying 257 passengers nearly crashed while taking off from Melbourne Airport after its weight had been miscalculated by 100 tonnes.
The Airbus A340-500 scraped its tail along the tarmac and grassland beyond the runway at Tullamarine on March 20, then hit airport landing lights and disabled a radio antenna before taking off.
The pilots then dumped fuel over Port Phillip Bay for about 30 minutes to reduce the weight before making an emergency landing at Tullamarine.
A preliminary report by the Australian Transport Safety Bureau says a weight entered into a computer put the aircraft weight at 100 tonnes less than its real tonnage.
The bureau's aviation safety director, Julian Walsh, declined to speculate on how close the aircraft came to disaster but said "there is no question in anybody's mind as to how serious it was".
A flight attendant also reported smoke in the cabin before the landing.
There has been speculation in aviation circles that the aircraft was seconds away from crashing.
The pilots discovered the incorrect weight reading in the laptop computer while they were circling Port Phillip Bay readying for the emergency landing.
The erroneous figure meant the thrust setting and reference speeds for take-off were lower than required for the aircraft's actual weight. The A340 was then "slow to respond'' when the first officer attempted to "lift off'', forcing the captain to quickly apply maximum thrust.
The two pilots - an American and European - resigned shortly after returning to Dubai in March. Emirates refuted suggestions they had been fired.
The accident caused "substantial damage'' to the aircraft, which has been parked at Tullamarine for the last six weeks. Airport staff later found parts of the plane, including a service panel, at the end of the runway.
Emirates also denied suggestions the A340 would be written off, saying it was yet to decide whether the aircraft would be repaired in Melbourne or at Airbus's base in Toulouse, France.
However, Airbus has said it will not repair the aircraft, saying: "Airbus is simply not in the aircraft repair business.''
The Emirates accident mirrors an incident involving a Singapore Airlines 747 in Auckland in 2003. Then, the aircraft scraped its tail along the runway after a pilot mistakenly entered an aircraft weight figure 100 tonnes lighter than that of the aircraft.
Emirates declined to comment about how close the aircraft was to disaster but said "we certainly accept that this was a serious event''.
The ATSB ruled out pilot fatigue or pressure on them to reduce costs as a cause of the accident.
The safety authority said human error would be the focus of an ongoing investigations. A final report will be not be released for at least another nine months.